Higher vehicle efficiency has been vigorously pursued by design engineers for all vehicles. Excessive parasitic power losses can generate multiple detrimental effects in vehicle operations, including lower effective working powers, decreased cooling efficiency, higher operating costs, increased noise and increased production of environmental pollutants.
Parasitic power losses for work vehicles, such as agricultural vehicles, earth-moving vehicles, off-road vehicles, loaders and/or the like, typically come from multiple sources. For example, for work vehicles equipped with power shift transmissions and/or continuously variable transmissions, one major source for power losses derives from the hydraulic system used to control the transmission pressure. Typically, the hydraulic system includes a pressure control valve configured to control the pressure of the hydraulic fluid supplied within the transmission at a fixed pressure value. This fixed pressure value typically corresponds to the pressure that is required to maintain the transmission clutches engaged when the work vehicle is operating at its maximum torque load (i.e., the pressure required to prevent clutch slippage at the vehicle's most severe loading conditions). However, more often than not, work vehicles are operated well below their maximum torque load. Thus, by maintaining the pressure of the hydraulic fluid at such a high, fixed pressure value even when a work vehicle is operating at lower load conditions, conventional hydraulic systems generate excessive power losses.
Accordingly, a system and method for controlling the pressure of hydraulic fluid supplied within a work vehicle transmission that reduces the vehicle's power losses would be welcomed in the technology.